<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>
<body>

    <div id="app">
        <button @click="generate">生成一个随机数字</button> <strong>{{len}}</strong>
        <ul v-for="number in numbers">
            <li>{{number}}</li>
        </ul>
    </div>

    <script src="https://cdn.jsdelivr.net/npm/vue"></script>
    <script>
        var app = new Vue({
            el: '#app',
            data: {
                numbers: []
            },
            computed: {
                len: function(){
                    return this.numbers.length;
                }
            },
            methods: {
                generate: function(){
                    this.numbers.push(Math.round(Math.random() * 100));
                }
            }
        })
    </script>

    <style scoped>
    </style>
</body>
</html>